Multiple-expansion internal-combustion engine



E A. SPERHY.

MULTIPLE EXPANSION INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY 18 191].

1 ,325; 8 1 0 Patented Dec. 23, 1919.

4 SHEETS-SHEET I.

[/MM 5. 5 mm: MEI. LIN;

URN II E. A. SPERRY.

MULTIPLE EXPANSIONINTERNAL COMBUSTION ENGINE.

APPLICATION FILED JULY 18.19II.

Patented Dec. 23, 1919.

4 SHEETSSHEET 2.

A TTOR/V E. A. SPERRY,

MULTIPLE EXPANSION INTERNAL comsusnow ENGINE APPLICATION FILED JULY 18.I91]. 1,325,810, Patented Dec. 23,1919.

4 SHEETS-SHEET 3.

LL. I I By 4/ CMWLJW v ATTORNEY E. A. SPERRY.

MULTIPLE EXPANSION INTERNAL comausnom ENGINE.

i-LPLICATION FILED JULY 18 19!].

1,325,810 Patented Dec. 1919.

4 SHEETSSYHEET4.

INVENTOR I. rm Tap STATES PATENT orricn.

.']ELMER A. SPERRY, F BROOKLYN, NEW YORK.

MULTIPLE-EXPANSION INTERNAL-COMBUSTION ENGINE.

Application sled July 18,1917. Serial No. 181,204..

To all whom it may concern:

Be it known that l, ELMER A. SrEnaY, a a citizen of the United States,residlng at 1505 Albermarle road, Brooklyn, in the county of Kings andState of New York, have invented certain new and useful Im provements inMultiple-Expulsion Internaltion engines including those of the multipletill expansion type, being of the general charac ter disclosed in my U.S. Patent No. 1,041,985 of June 8, 1915. More particularly, thisinvention relates to an improved means for "supplying fuel and air tothe engine, and for transferring the hot gases from the high to the lowpressure cylinder. Great .difiiculty has been experienced in engines ofthis character in keepingthe transfer valve between the high and lowpressure cylinder sufiiciently cool. lit is one of the princi al objectsof the inventionto provide an e ective means for keeping the saidtransfer valve cool without materially reducing the temperature of thetransfer gases.

Another object of the invention is to provide an improved means forinjecting the fuel into the high pressure cylinder by means of air undervery high pressure. The great degree of compression required .ispreferablyachieved in several stages and a.cooling of the air effectedbetween some or all of the stages. Various details of construction havealso been improved whereby the engine has been especially adapted foruse in propelling. submarines.

Referring to the drawings in which what l now consider to bethepreferred form of my invention is shown:

Figure 1 is a vertical section of a compound engine constructedaccording to my invention, the section being takenon line l1 of Fig. 2.

Fig. 2 is a plan view of the same.

Fig. 3 is an enlarged plan view of one of the combined transfer andinlet valves.

Fig. 4 is a vertical section of the same on' line H of Fig. 3.

Fig. 5, is a vertical section of the same on line 55 3.

Specification of Letters Patent.

Patented Dec. 23, 1919.

Fig. 6 is a horizontalsection of the valve on broken lines 6 6 of Fig.4.

Fig. 7 is a detail of the valve operating mechanism. I

Fig. 8 is a vertical section of the fuel feeding valve.

Fig. 9 is an elevation partly in section of the cooling means used tocool the air used for injecting over or in contact with the valvebetween the high pressure cylinder and the super-compressor.

Fig. 10 is a section on line 1010 of Fig. t8 Figs. 11 and 12 are detailsof construcion.

To illustrate my invention, l[ have taken the compound engineillustrated in Figs. 1 and 2 in which two high pressure or com bustioncylinders 1 and 2 are shown as placed on opposite sides'of the large lowpressure or expansion cylinder 3, whereby a symmetrical arrangement issecured. All the cylinders are suspended from a composite end plate 200,being detachably secured thereto by means of bolts 201 (Figs. 2 and 12).Said plate is shown as supported from the base or bed plate 202 by endcolumns or rods 203 and central columns 204. Preferably the lower end ofat least the low pressure cylinder is guided or bracedhy said columns(see Fig. 1). For this purposeears 205 may be provided thereon, whichare.

bolted or otherwise secured to the columns 204. By such a constructionany cylinder may readily be detached without removing the end plate 200,thereby effecting a great saving in the headroom required. The istonsland 5 of the high pressure cylin ers are connected to the crank shaft 6by piston rods 7-'8; while the piston 9 of the low ressure cylinder isconnected to said shaft by piston rod 10. Detachable wrist pins .206 and207 secure the piston rods to the pistons. By removing the extensionpieces 208 on the smaller cylinders or the hollow member 209 on thelarge cylinder, the pins may be easily driven out and the pistonsremoved. These particular features of en ine construction, while forminga part or t is invention, are not claimed specifically herein but arereserved fora divisional application about to be filed.

A fly wheel 104. is shown as bolted to the means the back pressure onthe valve is reducedso that it may be readlly opened and shaft 6..- Theexhaust valves for the low pressure cylinder are indicated at 115 and116. The said valves areoperated simultaneously by any suitable meanssuch as link 150 connecting two short bell crank levers 151 and 152, thelatter having a roller 153 bearing upon cam 154 on the cam shaft in theusual manner. Preferably the intake air for the high pressure cylindersis compressed before being admitted thereto. This may be accomplished byemploying the under side 11 'of'the low pressure piston 9 as an airpump, the admission of the air being controlled by puppet valve 12 andthe discharge controlled by a puppet valve 13.

From valve 13 the air is led through a pipe 14 into the reservoir ortank 15. From here it is carried by means of pipes 16 and 17 (see Fig.2) to the air supply valves 18 and 19. l

The two transfer valves20 and 21 are preferably located adjacent theretoand may be made as a partthereof, so that the two valves may beboltedinto openings in the.

top'of the engine. Leading to each of. said pairs of valves from eachhigh pressure cylinder is a restricted passage 22. Both the passage andhigh pressure cylinder are preferably water jacketed as indicated by theslots 100 and 101 in their walls. Said passage 22 opens into the lowpressure cylinder'through opening 23 which is normally closed by thevalve 20. The passage also extends across the top of valve 20, to thevalve 19 which is shown as composed of two valves and valve stems 25 and26 (see Figs. 3, 4 and .5). The stem 27 of the valve 21 is shown assupported in a hollow bushing 28 which is preferably provided withcooling ribs 29 thereon. Adjacent itsupper end said stem is providedwith a small piston 30 Working in a chamber 31. The upper side of saidchamber is in communication with the low pressure cylinder by means of ahole or bore 32 through the valve stem, while the lower part is incommunication with passage 22 by means of bore 33. By this closed. Thevalve is shown as normally pressed on its seat by colled spring 34, and

' is lifted to permit an exchange of gases between the cylinders bymeans such as bell crank lever 35 which has its outer end against said.pins by springs 43 and are designed to operate alternately with thetransfer valve 21. The supply air coming through pipe 16 into said valvecirculates through chamber 44 within hollow member 28' aroundcoolingribs 29 down through opening 45 and then around the bushing andout the opening 46, normally closed by the valve, thence through passage22 over the top of valve 21 and thence into the high pressure cylinder.When the inlet valve closes however and the transfer valve opens, thehot gases from the high pressure cylinder surge through the passage 22'and opening 20 into the low pressure cylinder.

Freferably the opening of the transfer valve is so timed that the lowpressure piston is approaching the top of the upward stroke. Furthermorethe exhaust valves 115- and 116 of the low pressure cylinder are closedbefore the end of the upward stroke of the piston 11 is reached. Thisresults in the pressure in the low pressure cylinder becomingapproximately equal to the terminal pressure in the high either transfervalve when the opposite one is opened to admit the high pressure gases.Upon the opening of the last named valve the compressed gases suddenlyfill the small clearance at the top of the low pressure cylinder andtend to lift the closed valve and blow into the other high pressurecylinder for a moment before the equalizing of the pressure on thetwosides of the valve through the opening 32 can take place. on theother hand, when the pressure in the low pressure cylinder is brought upto approximately that of the high pressure cylin-' der before port 23 isuncovered, the increase in pressure would be sufliciently gradual topermit the pressure on the two sides of the valves to be equalizedthrough passage 32, sothat there would be no tendency to open the closedtransfer valve, as'explained. The advantage is also secured by thismeans that the cle'arance in the expansion cylinder need not be reducedto a minimum but may and preferably is fairly lar e and also thaterosion of the valves an seats is lessened. This feature is not claimedbroadly herein, however, but is reserved for a copending application312,193 for valve mechanism for zilrtfinal combustion engines, filedJuly 21,

measure lt will readily be seen that the successive passage of thecomparatively cool incoming air over the top of the valve and alsoaround the valve stem will reduce its temperature sufficiently toprevent the hot transfer gases from damaging the same. At the same timethe valve will not be cooled to a'sul'liciently low temperature toseriously reduce the temperature of the transfer gases.

After the given quantity; of air supply is admitted to the high pressurecylinder, the valves and 26 are closed and the air in the cylindercompressed. Since the supply air has been already compressed by thepiston 11 as explained, the additional compression-in the high pressurecylinder raises the pressure to a fairly high degree. In order to supplyfuel in the engine under these con ditions ll prefer to make use of airwhich is COIUPI'QSSQCl to an ven greater extent. This super-compression,as it may be termed, may be accomplished in many ways, but is preferably accomplished in several stages to Jill avoid excessive heatingthereof. l prefer to abstract a small portion of the air compressed inthe high pressure cylinder and to further compress the same in a smallpump which is located on top of the engine and driven from an eccentric51 on the cam shaft 39. Said air is shown as taken out of the highpressure cylinder at 52 and lead to the pump 50 through pipe 110 and acooling means or coils 53, designed to cool the air before being furthercompressed and thereby till further increase the advantages obtained bya multi-stage compression.

The air is shown as led through a plurality of pipes 54 which arelocated within a casing 55 through which water or other cooling fluid isadapted to circulate. Apertures for the entrance and egress of the waterare shown at 111 and 112 (Fig. 9). The air is then led into the side ofthe pump through pipe 56 and port 56, The action of piston 50" incovering and uncovering port 56' times and governs the amount of airtaken from the high pressure cylinder, the air being withdrawnpreferably near the end of the compression stroke of the piston l. Fromthe pump, the air is led to the fuel valve 57 through pipe 58.- ApipeBlO is shown connecting the tuio pipes 58,Which acts as a reservoirand equalizer. The said valve is shown as comprising central valve stem59 having a valve 60 adjacent its lower end which is held ,on seatidllay spring 62 or the like. Surrounding said stem is a cylindrical member63 normally held down by a strong spring 119 and having flutes 11'?therein down which the incoming air and fuel are forced. The fuel isintroduced through the pipe 64.- from the fuel pump lid into the smallopening 65' and flows down into the chamber 66. soon as the valve opensthe fuel is atomiaed and blown out into the cylinder by the highlycompressed air. The said valve is shown as operated by lever 67 rockedby shaft 39 in a manner similar to the operation of the other valves.

- In accordance with the provisions of the patent statutes, 1 haveherein described the principle of operation of my invention, togethcrwith the apparatus, which I now con- 'sider to represent the bestembodiment thereof, but T desire to have it understood that theapparatus shown is only illustrative and that the invention can becarried out by other means. Also, while it is designed to use thevarious features and elements in the combination and relationsdescribed, some for having a portion thereof exposed to the cylindergases and a stem, means for conducting and dissipating heat rapidly awayfrom said valve through said stem including a metallic casing in whichthe stem is mov able, and an intake passage and valve adapted to guidethe current of incoming air into contact with said casing and stein.

2. In an internal combustion engine, the combination with a cylinderhaving a large clearance including a passage, a unitary structurecontaining an exhaust valve having a stem and an intake valve located insaid passage, means for opening and closing said valves during thecycles of operation, said valves being located adjacent each other andto the cylinder so that the intake air passes over said exhaust valveand stem to cool the same.

3. ln an-internal combustion engine, the combination with a cylinderhaving a large clearance including a passage, a unitary structurecontaining an. exhaust valve and an intake valveinsaid passage, meansfor openingand closing said valves during the cycles of operation saidvalves being located adjacent each other and to the cylinder with theintake valve farther therefrom than the exhaust valvef at. In a multipleexpansion engine, the combination with a high and a low pressurecylinder, of a transfer valve therebetween, an exhaust valve for thelast named cylinder and means for causing a circulation of other gasesor air in contact with said lld high pressure cylinder,'said intakebeing so located as to cause the intake air to 0001 said valve and stem.

6. In a combustion engine, the combina tion with a cylinder, of anexhaust valve therefor having a stem, a plurality of inlet Valves, andan mlet passage connected therewith, said inlet passage being-arrangedso as to cause the incoming air to pass'into sure cylinder, of anexhaust valve therefor,

close proximity to and on either side of said exhaust vali e and stem tocool the same.

7. In a combustion engine, a high presmeans for opening and closing saidvalve during the cycles of operation, an air pump and means for passinga current of cooling fluid from said ever it is closed.

\ 8. In an internal combustion engine, the combination with twocombustion cylinders and a common expansion cylinder, a transfer valvelocated between each combustion cylinder and the expansion cylinder,each valve having a plurality of surfaces, and means for alternatelycausing a circulation of coolinggases or air into contact with thesurface of each valve to cool the same. t

'9. In a multiple expansion engine, the combinationwith a high and a.low pressure cylinder, of a transfer valve therebetween, means foropening and closing said valve Iduringthe cycles of operation, and meansfor passing a current of cooling fluidoven said valve when it is closed.

10. In a multiple expansion, the combina- 'tion with a high and a'lowpressure cylinder, ofa transfer valve therefor, an inlet valve for thehigh pressure cylinder located adjacent said transfer valve, a commonpassage behind said transfer valve for the in coming andtransfer gasesand means for transfer gas valves between each high presopeningandclosing said valves alternately.

11. In a multiple expansion internal combustion engine, the-combinationwith a plurality of high and low pressure cylinders, of

sure cylinder and the low pressure cylinder, each of said valves beingprovided with an equalizing passage, an exhaust valve for the lowpressure cylinder, and means for closing said valve before the pistonreaches the end of'its strokewhereby the pressure in the low pressurecylinder is substantially equal to the pressure in the high pressurecylinder at the time either transfer valve is opened.

- 12. In a combustion engine a multi-stage compression for the-airsupplying the comthan those pump over said valve whenthe said ai bustioncylinder, a multi-stage expansion for the hot products, and cooperatingvalves acting between the stages on both the conipression and expansionportions of the cycles,'the portions handling the hot products beingvigorously washed by the said compressed air supply.

13. In a combustion engine a multi-stage compression for the airsupplying the combustion cylinder, a multi-stage expansion for the hotproducts, and cooperating valves acting between the stages on both thecompression and expansion portiohs of the cycles, the portions handlingthe hot products being vigorously washed by the said compressed airsupply and being less in extent portions of the valve exposed to 14. Ina combustion engine a multi stage compressionfor the air supplying thecombustion cylinder, a multi-stage expansion 3 for the hot products, anda cooperating valve arrangement acting between the stages on both thecompression and expansionportions of the cycles, the portions handlingthe hot productsv being vigorously washed bythe said compressed airsupply, and being pro- ..vided with extended surfaces in the path of thesaid compressed air supply.

15. In a combustion engine a multi-stage compression for the airsupplying the com-- bustlon cylinder, a multi-stage expansion for thehot products, and cooperating valves adapted for intensive heat exchangeacting between the stages on both the compression and expansion portionsof the cycles.

16. In a combustion engine a multi-stage compression for the airsupplying the combustion cylinder, a multi-stage expansion for the hotproducts, and a cooperating valve arrangement acting between the stageson both the compression and expansion portions of the'cycles, the saidvalve arrange- 1 ment being such that the portion handling ture.

ELWR A. SPERRY.

